ZIF-L/PDMS混合基质膜蒸气渗透耦合发酵强化乙醇生产效率的研究  

Enhancing ethanol production efficiency by ZIF-L/PDMS mixed matrix membrane via vapor permeation-fermentation coupling process

作　　者：王艳芳 毛恒 蔡玮玮 张傲率 徐李昊 赵之平 WANG Yanfang;MAO Heng;CAI Weiwei;ZHANG Aoshuai;XU Lihao;ZHAO Zhiping(School of Chemistry and Chemical Engineering,Beijing Institute of Technology,Beijing 102488,China)

机构地区：[1]北京理工大学化学与化工学院,北京102488

出　　处：《化工学报》2021年第10期5226-5236,共11页CIESC Journal

基　　金：国家自然科学基金重点项目(21736001)。

摘　　要：蒸气渗透(VP)膜分离不存在膜污染风险,在生物乙醇生产中具有广阔的应用前景。将聚二甲基硅氧烷(PDMS)膜和以二维沸石咪唑骨架(ZIF-L)为填充基质制备的PDMS (ZIF-L/PDMS)混合基质膜,分别用于VP膜分离与菊粉水解液发酵制乙醇过程的耦合,分析了二者在耦合过程中的分离性能和发酵性能。探究了不同膜分离方式、不同类型膜及操作条件对膜分离性能的影响。实验结果表明,当料液浓度为5%(质量)、蒸气循环流量为1.5 L·min^(-1)时,ZIF-L/PDMS混合基质膜的VP性能高于渗透汽化(PV),归一化总通量达到1148.78 g·m^(-2)·h^(-1),分离因子高达19.14,显著提升了乙醇分离性能。ZIF-L/PDMS混合基质膜用于VP耦合发酵,实现了耦合过程的高渗透性和乙醇选择性,与文献报道相比,乙醇移除效果最优,乙醇产率和时空产率分别达到0.421 g·g^(-1)、3.07 g·L^(-1)·h^(-1),两个指标明显高于单独发酵,极大地提高了乙醇生产效率。因此,ZIF-L/PDMS混合基质膜在原位分离发酵乙醇方面具有很大的应用潜力。Vapor permeation(VP)membrane separation does not have the risk of membrane fouling and has broad application prospects in the production of bioethanol.The polydimethylsiloxane(PDMS)membrane and the novel PDMS mixed matrix membrane(ZIF-L/PDMS)prepared by embedding two-dimensional zeolitic imidazolate framework-L(ZIF-L)into PDMS matrix were used as separate modules to separate ethanol from fermentation of inulin hydrolysate in a VP coupled with fermentation system(VP-fermentation).The separation performance and fermentation performance during coupling process were analyzed.The effects of separation methods,membrane types and operation conditions on the separation performance were explored.The results showed that ZIF-L/PDMS mixed matrix membrane for the separation of 5%(mass)ethanol aqueous solution by VP showed better performance than pervaporation(PV)when vapor cyclic flow was 1.5 L·min-1,and the normalized total flux and the separation factor reached 1148.78 g·m^(-2)·h^(-1) and 19.14,respectively,suggesting the ethanol separation performance was significantly improved.Furthermore,the ZIF-L/PDMS membrane exhibited an impressive permeability and ethanol selectivity in VP-fermentation process.Compared with the literature reports,it achieved the best ethanol removal effect,which greatly enhanced the ethanol production efficiency.The ethanol yield and productivity reached 0.421 g·g^(-1) and 3.07 g·L^(-1)·h^(-1),respectively,which were higher than that in independent batch fermentation.Therefore,ZIF-L/PDMS mixed matrix membrane exhibits great application potential in the in-situ removal of ethanol from fermentation.

关 键 词：聚二甲基硅氧烷 混合基质膜 乙醇发酵 蒸气渗透 膜分离 

分 类 号：TQ028.8[化学工程]